Geothermal energy
Heating new construction areas with mine water

In the Ruhr region there are countless mine shafts with access to deep underground strata. Of these, about 120 relevant sites are being taken into account in the project where it is possible to utilise heat from mine water. The existing heat potential shall be principally utilised at sites where mine water will need to be permanently removed in future. The selection of suitable mine water discharge points will be based on economic and ecological aspects – as a basis for investment planning and subsequent implementation at the individual sites.

The core idea of the research project is to reduce climate-damaging emissions through the use of mine water. For this purpose, sustainable approaches to heat utilisation are being developed, taking into account the mining infrastructure, and evaluated in software, energy efficiency and environmental terms. The focus here is not on a specific location but on the area-based consideration of all shafts as a potential heat source and the surrounding structures as a potential heat sink. If the work is to succeed it is important not only to develop the most technically sensible solutions in planning terms but also to involve potential heat consumers in the process. It is intended that the project, which will run until 2019, shall deliver decision-ready implementation concepts at selected locations. These will provide the basis for the later implementation and the planned operational monitoring.

The project management and coordination of the research work is being carried out by the Chair of Energy Systems and Energy Economics (LEE) at Ruhr Universität Bochum. Eimer Projekt Consulting (EPC) is responsible for the strategic initiation of contacts and the permanent inclusion of potential heat consumers through suitable participation formats. RAG AG as the site owner will mainly support the implementation and investment planning, while DMT GmbH & Co. KG is responsible for the technical planning work together with the LEE.

Mine drainage as an eternal task of RAG (formerly Ruhrkohle AG) provides the starting point for considering the different heat utilisation concepts. First, the relevant sites will be identified as a potential source of heat and each of the 120 sites categorised. Based on this categorisation, the heat sinks at the sites will then be investigated in descending order to define suitable areas. Parallel to this, the TOP-Energy software will be used to develop technical heat utilisation concepts that serve as a baseline scenario. These can be accordingly adapted to the respective category.

In addition to the energy yield, the software will also be used to investigate the economic viability and ecological benefits of these concepts. Potential customers and other stakeholders are being included in the activities since the results of the investigation will then be bundled into an implementation concept that will highlight the various potential and restrictions for utilising mine water.

Collaborations with partners from science, authorities and industry will serve to ensure the project progress. These will help to gain additional knowledge and experience, as the use of mine water for supplying energy is largely unexplored apart from a few pilot projects.

The heat utilisation concepts being developed in the project will be evaluated and tested with the TOP-Energy software program in terms of energy efficiency, economic and ecological aspects. The calculations will incorporate the experience garnered by manufacturers of technical systems (such as heat pumps, networks) with whom the project consortium is actively sharing ideas.